Tube-bending apparatus



Aug. 28, 1951 J. w. ARMSTRONG ET AL TUBE-BENDING APPARATUS Filed Aug.27. 1949 15 Sheets-Sheet 1 Z Z/ZELA/TOBS 5EE/VARD E FBANK Aug. 28, 1951J. w. ARMSTRONG ET AL TUBE-BENDING APPARATUS l5 Sheets-Sheet 2 FiledAug. 27, 1949 BEKNARD E FRANK X 7 HM M42115 T/PoN 4.4% 1211a rroe/vav sk Aug. 28, 1951 .1. w. ARMSTRONG ET AL TUBE-BENDING APPARATUS Filed Aug.27, 1949 15 Sheets-Sheet 4 1951 J. w. ARMSTRONG ET AL 2,565,940

TUBE-BENDING APPARATUS l5 Sheets-Sheet 5 Filed Aug. 27, 1949 2 8N0 5 M?m /4W 4 MN A. a

Aug. 28, 1951 J. w. ARMSTRONG ET AL v 2,565,940

TUBE-BENDING APPARATUS Filed Aug. 27, 1949 15 Sheets-Sheet e Aug. 28,1951 J. w. ARMSTRONG ET AL 2,565,940

TUBE-BENDING APPARATUS Filed Aug. 27, 1949 15 Sheets-Sheet v If w /22553 420 5 F34 NK Kllam'v ABMs-[B0146 Aug. 28, 1951 J. w. ARMSTRONG ETAL2,565,940

TUBE-BENDING APPARATUS Filed Aug. 27, 1949 15 SheetsrSheet 8 XJOI/MM/leMsre 0N6 Aug. 28, 1951 J. w. ARMSTRONG ET AL I 2,565,940

TUBE-BENDING APPARATUS Filed Aug. 27, 1949 15 Sheets-Sheet 9 //v ve/v me558M420 1 FeA/vn 6X Jmv MAB/vs TBONG WM r 2255021 14 T ToE/VE-YS Aug.28, 1951 -J..w. ARMSTRONG ET AL TUBE -BENDING APPARATUS l5 Sheets-Sheet10 Filed Aug. 27, 1949 Aug. 28, 1951 J. w. ARMSTRONG ET AL TUBE-BENDINGAPPARATUS Filed Aug. 27, 1949 15 Sheets-Sheet ll Aug. 28, 1951 FiledAug. 27, 1949 lssheets-sheet 12 3 Y swi fizz??? J. w. ARMSTRONG ET AL2,565,940

' TUBE-BENDINQ 'APPARATUS' 195.1 J. w. ARMSTRONG ET AL 2,565,940

TUBE-BENDING APPARATUS 15 SheetsSheet 14 Filed Aug. 2'7, 1949 g Q www.Aug. 28, 19 I J. w. ARMSTRONG ET I 4 .TUBE-BENDING APPARATUS I FiledAug. 27, 1949 I V '15 Sheets-Sheet 15 N VE/V Tazs COU/V TEE CLOCKW/SEBEND cz 0 CK vv/sE BEND THE/E ATTORNEYS Patented Aug. 28, 1951TUBE-BENDING APPARATUS John W. Armstrong and Bernard E. Frank,Rochester, N. Y., assignors to General Motors Corporation, Detroit,Mich., a corporation of Dela- Application August 27, 1949, Serial No.112,792

9 Claims. 1

This invention relates to the manufacture of tubing serpentinescomprising straight portions and'l80 bent portions.

An object of the invention is to provide a machine for bending aplurality of pieces of tubing simultaneously into serpentine shape. Inthe disclosed embodiment of the invention, this object is accomplishedby a combination of elements comprising a pair of grooved rolls,parallel rods on which the rolls are respectively journaled, a supportto which the rods are attached and which so spaces the rods that thegrooves of the rolls combine to form openings into which the pieces oftubing closely fit, rotators respectively in axial alignment with therods, devices respectively for effecting the turning of the. rotators inopposite directions for normal position and return to normal position,means for effecting the conpling of one rotator with the rod support andthe uncoupling of the other rotator from the rod support whereby, duringthe turning of the coupled rotator, the rod not aligned with thatrotator will move orbitally about the axis of the rod aligned with thatrotator, and vice versa, means for retaining in fixed position theportion of tubing leading to the rolls during the bending operations,and means for longitudinally feeding a certain amount of tubing betweenthe rolls prior to bending operations.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings, wherein a preferred embodiment of the present invention isclearly shown.

In the drawings:

Figs. 1 to 8 are diagrams showing the various steps in the operation ofthe bending'machine.

Fig. .9, Sheet 2, and Fig. 13, Sheet 3, together form a top view of themachine.

of Fig. 11.

Fig. 12 is a sectional view on the line l2-l2 of Fig. 10.

Fig. 12A is'a sectional view on line i2A-I2A I of Fig. 10.

Fig. 15, Sheet 4, is a plan view of a machine showing the left end ofFig. 9 and is drawn to a larger scale than Fig. 9, the part in sectionbeing on line l5-l5 of Fig. 16.

Fig. 16 is a view in the direction of arrow l6 of Fig. 15.

'- Fig. 17 is a view in .the direction of arrow l1 of Fig. 15, theportions of Fig. 17 which is insection being taken on the line |ll'l ofFig. 15. Fig. 18 is a sectional view on line Iii-l8 of Fig. 16. i Y

Fig. is a bottom view in the direction of arrow 25 of Fig. 24.

Figs. 26 and 2'7 are sectional views on the lines 23-26 and 21- -21,respectively, of Fig. 24.

Fig. 28 is a plan view of a turn-table N of Fig. 10, said view beingtaken in the direction'of arrow 28 of Fig. 10.

Fig. 29 is a view similar to Fig. 28, showing the table N in a differentposition.

Fig. 30 is a sectional view on the line-30--3ll of Fig. 29. v

Fig. 31 is a view on the line 3l-3l of Fig. 10,

. showing a motion check mechanically associated with the turntable.

Fig. 32 is a sectional view on the line 32-32' of Fig. 29. a g

Fig. 33 is a sectional view on the line 3-3-33 of Fig. 16, showing thebending rolls and operating mechanism.

Fig. 34 is a fragmentaryview in the direction of arrow 34 of Fig. 40.

Fig. 35 is a sectional view on the line 35-35 of Fig. 33.

Fig. 36 is a sectional view similar to Fig. 33,

' showing certain parts in other positions.

Fig. 3'7 is a sectional view on the line 31-31 of Fig. 36.

Fig. 38 is a sectional view on the line 32-38 of Fig. 37.

Fig. 39 is a sectional view on line 3939 of Fig. 36. V

Figs. 40 and 41 together form a sectional view on the line 4ll- 4ll ofFig. 36. p

Fig. 42 is a sectional view on the line 4242 of Fig. 33. g

Figs. 43 and 44 together form an hydraulic and an electrical diagram ofthe machine.

Figs. 45 to 49 are side views of the Various cams included in thediagram shown in Fig. 44.

Fig. 50 is a plan view of the valve controlling Referring to Fig. 1, thetubing T is passedthrough a guide C and between grooved bending rolls Aand B. While roll B remains fixed, roll A moves orbitally from itsinitial prisition as represented by the dot-dash circld'A inFig. '2, toposition A, to cause the tubihgtobe'bent 180 around roll B. Roll A thenreturns to its initial position, as shown in Fig. 35, The tubing T isfedagain, as shown in Fig. 4, and roll Bis caused to move from itsinitialposition represented by dot-dash circle B in Fig 5, orbitallyaround roll A to position B. Roll B then returns to its initialposition, asshowndnFig. 6. This cycle of operations is'repeated}th'tubihg being'fed again as shown in Fig. 7 and roll A is caused tomove orbit-allyareiirid rell-B to position A as shown in Fig. 8. Thesecycles continue as long as necessary to' fornfi' -tfie length of tubingin the required number of straight portions joined by 180 arcanepersons;

Figs. 13 and 14 show the left portion ofa rack ror'suppoitm'g asi'ip'ply of lengths of tubing.

This rack comprises a plurality of upright frames I, attached tohoriaental'angl'es i ihe rack, as shown in Figs. 13 and 14, extends tothe right a distance sufili'ent to support the tubing.

Referring to Figs. 9 and 10, legs 3 support side bars 4 which'siipporta'main table plate 5 and a shorter plate 5a. Plate Sabad the lefthandframe'l (Figs.=l3 and '14)- Sunporta feed cylinder 6 receiving'a piston!(Fig. 44'), connected by rod-8 with a pl'ate 9, guided by rails N (Fig.12), attached'to-"plate Band spaced by bars [0. The slide 9 is meved'between stops provided by screws l2 and (Fig. 10) threaded,respectively, through brackets 14 and I5, the latter being attached tothe-plate 5' and the former being attached to the plates I I (Fig. 12)and provided with a vertical prtion it having a notch H for receivingaplurallty of tubing lengths stacked vertically. The slide'il'su'pp'orts a plate 38 (Figs. 10,-22-25, '27) whichguidea block; 19(forming part of the tube-clamping device M shown in Fig. 10) anmovement at right angles to rails H and thedirectioii of movement ofslide 9. Block H! is retained uponTplate ill by plate 2i? secured byscrews 21 Block l9 is'connected with a rod 22 connected with a piston 23(Fig. 44, top) I rec'ivedby a cyli'nder 24 which screws 25 attach toplate l8. A spring 26 (Fig. 44) in cylinder 24 u'r'gesnie-p stta 23 leftin Fig. 44, or right in Fig. 22, normal-ly'to separate thetubing'clampingjaws'. Jaw"?! is attached to block [9. The other jawcomprisesa plurality of plates 28, each banne s-concave surface 29 inalignment with a concave surface '33 of jaw 21. Thus, the jaws areadapted 'toclamp the plurality of lengths of tubing stacked vertically.Jaw 21 is located abovefa plate 32 upon which the jaws 28 are placed. aThe jaws '28 are movable horizontally and are guided for such movementby U-shaped member 33 (Fig. 26) which, together with thep'late 32 and acover 35, are attached to plate Ia screws 34; A rubber block 33, locatedbetween the jaw plates 28 and the member 33 providesaresilientbackingwhereby the tubes are yleldingly-clainped and each tube isgripped by the same amount of pressure. A screw 3'! passes through thecover 35 and larger holes 38 in jaw plates 28 and is screwed into theplate I8. The clearance between screw 31 and holes 38 permits the jawplates 28 to adapt themselves to thetubing lengths which they engage.

Block 20 is attached by a bar 40 and a pin 4| to a cam 42 having ahandle 43. Pin 4| is received by a notch 44 in a lug 45 of plate l8.When cam 42 is in the position shown in Fig. 2, the retraction of jaw 21is limited by virtue of engagement of earn 42 with plate 18. If handle43 is moved clockwise (Fig. 22), the jaw 21 is manually advanced toclamping position.

Referring to Figs. 9 and 10, the plate 5 supports brackethaving-overhanging portions 5| supporting bar 52 and connected by screws53 (Fig. 17) to a frame 54 attached to a bar 55 by screws 56 andattached at its left side (Fig. 16)

to 9. plates? by screws 582 The frame 54 guides vertically movable bars59 and 60 which are caused to move by cams 3! and 62,- respectively,connected by rods' fifi'a'nd 84 with pistonsfili' and 65, respectively(Fig. 44 ,and cylinders 61 and 68, respectively, which are supported bythe bar 55. Each of the cams 6i and 62 has a diagonal or slanting rib 69for engaging a slanting groove in the bar so that horizontal movementsof the cams cause vertical movements of the bars. These bars 59 and 3Bare caused'to move alter nately in opposite directions 'so'that whenonev is down, the other will be up.

The brackets 59 support a tubeguide 10, one end of which is attached tothe crossbar 52 and the other end is connected by a screw II with ablock 12 attached to a plate I3 which screws 14 attach to the frame 54which supports a bracket 55 attached to frame 54 by screws 53 (Figs. 16and 17). A member 15 of channel shaped formation is attached to block 12and has its side flanges 13 joined at'their bottoms by-a'plate ll andthese flanges are provided with; a horizontal row of holes 78. Theseholes are provided to permit insertion of small pins therein. These pinsare in alignment with the plate- IIS and serve to separate the upperfive tubes. from the lower group of five tubes. Theflangcs are beveledat 79 (Fig. 21) to facilitate the entrance of the tubing between theflanges and are beveled at 80 so that the member 12 can tor-- minateclose to the grooved bending rolls A and 3. Movement of the cams-Bl and62 (Fig. 15)- to the right is limited by step screws 8! threaded througha plate 32 integral with bar 55.

During the bending operations performed by rolls A and B, as shown inFigs. 1 to 8, it'is; desirable to support the-tubing as it is bent. Forthis purpose, a'rotary table N (Figs.- 9,10, 28 and 29) is provided.Table N comprises a plate 83 attached to a framework comprising parallelangles 84, a bar 85, and diagonal bars 85a and 85b. Bars 85a and 85b aresupported by rollersBS (Fig. 32) which roll on the'plate;

5. Bars 85a and 85b support (Fig. 29), the

Check 95 is attached to a pad 96 supported by one of the cross channels3a connecting legs 3 (Fig. 10). Check 95 has an arm 91 connected by link98 with a lever 99 pivotally supported by a bearing stud I99 supportedby a member I9I which is part of a framework I92 extending from andattached to the frame which supports the plate 5, as shown in Fig. 10.Lever '99 has a hole I93 for receiving the rod 99 and lever 99 isreceived between collars I94 (Fig. 30) pinned to the rod 99. In oneposition of table N, as shown in Fig. 28, the axis of rod 99 will be atd (Fig. 31). The connection of the other end of lever 99 with link 98 isrepresented by a, and the connection of check arm 91 with link 98 isrepresented by '22. During the 180 rotation of table N in a clockwisedirection, as viewed in Fig. 28, the axis of rod 99 moves from d to d"and passes through a position d, and the shorter end of lever 99 movesfrom a to a" and passes through a position a. During movement from d tod, a moves to a and b moves to b The check 95 does not retard movementfrom b to b but, during movement from d to d", this movement is retardedby the check 95 as the end of lever 91 moves from b to b, which positionis occupied when rod 99 is at d" and the shorter lever end is at a".Consequently about the first half of the clockwise rotation of table Nis free and the remaining portion is retarded as the table moves fromthe position shown in Fig. 28 to that shown in Fig. 29. Similarly, asthetable is moved from the position shown in Fig. 29 to that shown in Fig.28, about the first half of said movement is free and the remainingportion is resisted by the check. Consequently the shock of stopping thetable is minimized.

Referring to Fig. 33, the bars 59 and 69 have sockets I99 and H9 inalignment with rods III and H2 which pass, respectively through twogrooved rolls A and two grooved rolls B. The upper set of rolls A and Bis separated from the lower set by a plate II3 through which the rodspass. These rods pass also through a plate II4 secured to the rods byset screws H5 and are secured to a plate I29 which screws I2I (Fig.

3'7) secure to a latch plate I22 having a notch I23 for receiving alatch lever I24 pivotally supported by a pin I25 attached to a gear I26supported by plate 5 and rotatable in a bearing I21 provided by drum 68.The gear I26 rotates on ;an axis in alignment with the axis of rod IIIcarrying rollers A. The lever I24 is received by a pocket I 28 in gearI26 and a spring I29 urges the lever I24 toward the notch I23 of thelatch plate I22. As shown in Fig. 33, lever I24 has been retractedfromthe notch I23 due to the engagement of said lever with a tongue I39provided on the upper end of a shaft or rotator I3I which is slidablevertically in a bearing I32 provided by a plate I33 which screws I34(Fig.

39) attach to plate 5 and in bearings I35 and connected by'a pin I42with plate I22 to which plate I29 is attached.

The threaded lower end of shaft I3I (Fig. 33) is secured by a nut I43 tothe inner race of a ball -thrust bearing I44 whose outer race isreceived by a cup I45 and isretainedby' a plate? I46 at- I tached to thecup by screws I41. Cup I45 is 6 connected by a rod I48 with a piston I49(Fig. 44) in a cylinder I59 clamped by a-screw I5I between clampingportions I52 of the bracket I39. When the piston I49 moves up the shaftI3I is connected with the shaft MI by the en-- gagement of tongu I39with the notch I49 in; shaft MI and the lever I24 is retracted fromthenotch I23 of plate I22 so that the plate I22 may be rotated by shaftI3I, thereby causing the rollare A to move orbitally around the rollersB, as shown in Fig. 2, and then back again to the normal position, asshown in Fig. 3. These movements .are effected by a mechanism whichcomprises a gear I55, which screws I56 attach toflange I51 of shaft I3I.Gear I55 mesheswith a rack I58 guided horizontally by a block I59attached to plate 5 by screws I15 (Figs. 33, 40). Rack I58 is connectedwith a rod I6I, connected with a piston I62 (Fig. 43) in a cylinder I63attached by brackets I94 and screws I to plate- 5. Admission of pressurefluid to that end of sure fluid at the upper end of cylinder I63 causes.

return of rollers A to normal position.

In preparation for movement of rollers B'- orbitally from normalposition, shown in Fig. 4,. to the position of B shown in Fig. 5,pressurefluid is admitted to the upper end of cylinder I59 (Fig. 33) tocause disengagement of shaft I3I' from shaft MI and the latching ofplate I 22 to the gear or rotator I26 by engagement of lever I34 withthe notch I23 of plate I22 due to the: action of spring I29. After thishas been'done,v the gear I26 can be rotated on an axis which is inalignment With the axis of rod I I I which carries rolls A. Themechanism for rotating the gear I 29 comprises a gear I19 (Figs. 39 and34) attached to a shaft I1I journaled in a bearing I12 provided by plate5 and in a bearing I13 provided by a plate I14 which is attached toguide I59 by screws I15a (Fig. 33) and which is attached by screws Ituato a guid I19 attachedv to plate 5 by screws I69 (Figs. 33 and 40).Guide I16 supports a rack I11 meshing with a gear I19- attached to shaftI1I. Rack I11 (Fig. 40) is connected by a rod I19 with a. piston I89(Fig.

43) in a cylinder I8I attached to plate 5. Ad-- mission of pressurefluid to that end of cylinder ,I8I which appears as lower in Fig. 40,causes counterclockwise movement of shaft I1I as viewed from above toeffect clockwise movement of rollers B orbitally around rollers A fromthe position shown in Fig. 4 to that shown in Fig. 5 at B; and admissionof pressure fluid to the other end of cylinder I8I causes roller B toreturn to normal position. Screws I92 and I83 (Fig. 39) threaded,respectively, through bars I84 and I85, which space plate I14 from plate5, are

engageable, respectively, by racks I53 and I11,

stopped in a definite position by engagement of a stop screw I26bthreaded through'a post I26a attached to gear I26 with a bar I260attached to plate 99.- On the return movement of shaft I4I after theleft-hand bend, shaft MI is stopped in a definite position-by'virtue ofthe engagement with stop I22aattached to gear I26 ofthe-plate I22connected with shaft I4I.

During movement of rollers A crbitally counterclockwise around the axiscf'rollers B, the table N (Figs. 28 and'29) is caused to movecounterclockwise from the position shown in Fig. 29 to that shown'inFig. 28 by virtue 'of engagement of an arm I86 clamped'by'a screw I850.(Fig. 33) to a disc I81 connected with shaft I3I by keys I88 received bygrooves I89 in said shaft. Therefore, during the bending of the tubingaround rollers B by counterclockwise orbital movement of rollers A, thetable N is oausedto' move counterclockwise with the tubing'as it isbent. During return of rollers A to the normal position, the table N isnot rotated'but remains in the position shown in Fig. 28. During thebending of the tubing by orbital clockwise rotation of rollers B aroundthe axes'of rollers A to position B' shown in Fig. 5, the table N iscaused to move clockwise by virtue of engagement with rod 90 by a leverI90 (Fig. 33) whose hub -I9'I is clamped by'a screw I9Ia (Fig. 42) tothe hub of a gear I92 on a bushing I93 through which the'shait I3Ipasses eccentrically' of the bushing. Gear I92 meshes with a gear I94(Fig. 34) connected with shaft I'II. When rack III' moves up in Fig. 40to cause clockwise movement of gear I26 as viewed from above, arm IQBmoves clockwise to cause, by virtue of engagement with rod 90, rotationof table N from the position shown in Fig. 28 to that shown in Fig. 29.When rack I11 moves down in Fig. 'to effect counterclockwise movement ofrollers B to normal position shown in Fig. 6, arm I38 returns bycounterclockwise movement to its normal position but table N remains inthe position shown in Fig. 29 ready to carry the work as it is movedfrom the position shown in Fig. 7 to that shown in Fig. 8.

In Figs. 28 and 29 the approximate position of the actuating arms I86and I90 with respect to the rod 90 which is moved thereby to oscillatethe table N, is shown in dotted lines. The rod I86, when inoperative,occupies a position to engage the rod 2i] on the upper side of such rodas viewed in Fig. 29. The inoperative position of arm When the arm I86is rotatedin a clockwise direction by its ope'ratingmeans, it engagesthe rod '30 and moves the table N to the Fig. 29 position,

To facilitate'proper meshing relation of gears I92 and I94, the bushingI93 may be rotated about the shaft I3I by applying a spanner wrench toits notches Iilta. The bushing I93 is retained in adjusted position bytightening screws I931) (Fig. 33) which clamp it against the bracketarmI38.

Referring to Fig. 44, a motor 262 drives a low pressure, high volumepump 20I and a high pressure, low volume pump 262 connected, re-

spectively, with inlet pipes 203 and ifll'into which oil flows throughfilters 205 and'ZiEQrespectiVely, 7 from a tank 237.

V The outlet of pump 20I is connected through a by-pass controllingvalve 208 and a flow control valve 299with a pipe 2 II] which isconnected with mechanically controlled valves 2I I, 2I2, 2I3, 2M and2I-5'whoseactuators are-controlled respectively by cams 216, 2 I1, 2 I8,

I90 is similarly indicated in Fig. 28. 1.

2I9 and 220, the contours of which are shown, respectively; in Figs; 45,46, 47, 48 and 49. These camsare rotated by-a shaft 222 (Fig. 50)rotatably supported by hearing brackets 223 and 224 mounted on a plate225to which the valves 2I I2I5 are fixed. Shaft 222 is connectible-by aclutch 226 with a pulley 221 connected by a belt 228with a pulley 229connected with the output shaft of a gear reducer, whose input shaftisdriven by an electric motor 23I (Fig. 43). Normally, the clutch 226 isdisengaged through thea'ction of a spring 232 connected with a lever 233(Fig. 50) which is pivoted at 234 and urged clockwise by the spring 232,said lever carrying shoes 235 received by a groove in a collar 236which, when in the position shown in Fig. 50, causes-the'c lutch 226 tobe disengaged. Lever 233 is also connected with the armature'23'l of asolenoid 238, which, when energized, causes the collar 236 to-move-rightto effect engagement of the clutch."

Wires 24I, 2'42, 243 (Fig. 43) connectedwith a source of alternatingcurrent can be connected with pump motor 200 by a three-pole switch 244and a relay switch 245 having a magnet coil248 under control by a startswitch 247 and a stop switch 248. Switch 244 and switch 249, whenclosed, effect connection of a primary winding 25I of a transformer 25!!with wires 24I and 243 and the connection of wires 253 and 254 withwires 242 and 2 4I. Wires 253 and 254are connected'with contacts of arelay switch 255 having a magnet coil 256. The energization of coil 256causes wires 253 and 254 to be connected with solenoid 238 and with asolenoid 251 controlling a valve 258 for a purpose to be described. Thecoil 246 of relay switch 245 is. connected with the secondary 252 oftransformer 250 through a circuit which requires the closing of switch241 for initial energization of coil 246 after which its circuit ismaintained by a closed contact of this relay switch. The open-circuitingof coil 246 is effected by opening the normally closed stop switch 248or by the opening of normally closed overload switches, each having abimetallic blade 259. Motor 200 is-started by closing switch 241 and isstopped by opening switch 248 or by the opening of any of the overloadcircuit breakers.

Electric motor 23I is connected with current source wires2iil, 2G2 and263 by a relay switch 265 having a magnet coil 225 and controlled in thesame manner as the relay switch 245 which controls motor 200. Motor 23Istarts when a starting switch 251 'is closed and stops by the opening ofa stopswitch 2 68 or by opening either of the overload circuit breakers269. The connection of coil 256 of relay 255 with transformer secondarycoil 252 is controlled by a safetyswitch 270 and by a switch in'seriestherewith andprovided by a counter 2' (available. on themarket) which isprovided with a switch which automatically opens when the counter hascounted to a certain number. The operation of the counter is controlledby the shaft 222 which, as shown in Figs. BIL-52, rotatesa rod 212counterclockwise into engagementwith a pin 213 carried by a lever 214which operates the counter. As lever 214 is moved clockwise by rod 212,the pin 213 moves out of the path of:movement of rod 272' whereupon aspring provided by the counter returns the lever 214 to normal position.For each :rotation of shaft 22-2, the counter adds two. When the counterhas counted to a certain numbena counter controlledqswitch (not shown)opens. and the coil 256 of relay 255 is open-circuited and solenoid 238is deenergized to permit the spring 232 to disengage the clutch 226 andthe solenoid 25! is deenergized to cause the valve 258 .to connect withdrain or tank 281. Pressure in a pipe 288, connected with valve 288(Fig. 44) is relieved, thereby causing valve 288 to connect the outletof pump 28I with the tank so that the pump 28I will operate withoutforcing the fluid into the pipe 2I8. The outlet of pump 282 also isconnected through a by-pass controlling valve 28| and a flow-controllingvalve 282 with a pipe 283. Whenever valve 258 opens, valve 28I, likevalve 288, is conditioned for connecting the outlet of pump 282 with thedrain. In Figs. 43 and 44 the return to drain is indicated by T;

The function of valve 2| I is to connect pipe 2I8 with a flexible pipe285 connected with a head end of cylinder 24, thereby causing the tubingto be clamped to the feed slide and the valve 2| I operates at theproper time to relieve the pressure in pipe 285 so that the spring 26will retract the movable clamping member 21 (Fig. 23).

The function of valve 2 I2 is to connect pipe 2 I 8 with one or theother of pilot pressure pipes 2 I 2a,

'2I2b so that a valve 286 is conditioned to connect pipe 2I8 either witha pipe 281 or a pipe 288 connected with the ends of the feed cylinder 6.If pipe 281 is connected with pipe 2I8, pipe 288 will be connected withdrain pipe 289 of valve 286, and vice versa.

The function of valve 2 I3 is to connect pipe 2 I 8 1 with one or theother of pilot pressure pipes 2 I 3a, 2I3b for conditioning a valve 298(Fig. 43) to connect pipe 283 with a pipe 29I or with a pipe 292connected with cylinder I88. If pipe 29I is connected with pipe 283,pipe 292 is connected with pipe 293 of valve 298 leading to drain, andvice versa.

The function of valve 2 I5 is to connect pipe 2 I 8 with one or theother of pilot pressure pipes 2 I511, J 2I5b (Fig. 44) for conditioningvalve 295 to connect pipe 288 with pipe 296 or with pipe 29Ic'onnectedwith cylinder 63. If pipe 283 is connected with pipe 296 by valve 295,pipe 29! is connected with drain pipe 298 of valve 295, and vice versa.

The function of valve 2 I4 is to connect pipe 2 I 8 i with one or theother of pilot pressure pipes 2I4a, 2I4b to condition valve 388 toconnect pipe 283 either with pipe 30I or pipe 382 connected withcylinder I58. If pipe 283 is connected with pipe 38!, pipe 382 will beconnected with drain pipe disconnected from the gear I26 preparatory toorbital rotation of rolls A around rolls B. Therefore, it is necessarythat support 59 be up and support 68 be down, as shown in Fig. 33.Therefore, concurrently with the admission of pressure fluid to the pipe382 pressure fluid is admitted through a pipe 385 to the head end ofpiston 61 and to the rod end of piston 68, thereby causing supports 59and 68 to move into positions shown in Fig. 33. When valve 388 connectspipe 283 with pipe 38I for the purpose of disconnecting shafts I3I andMI so that rolls B can move orbitally around the axes of rolls A,pressure fluid is admitted through pipe 386 through the rod'end of thecylinder 61 and the head end of cylinder 68 so that support 59 will movedown and support 68 will move up to the positions shown in Fig. 36.

Fig. 54 shows the timing of the valve operation for one clockwiserevolution of shaft 222 and the five cams shown in Figs. 45-49, theirfollower F being shown on the same side of the cams for {convenience infollowing timing diagrams as shown in Fig. 54. Since the followers ofcams 2|! and 2I9 are located on the side opposite the followers of cams2I6, 2I8 and 228, cams 2" and 2 I 9 are actually inverted from theposition shown in Figs. 46 and 48. The cycle may be considered asstarting with the followers F about 15 from vertical as viewed in Figs.45-49.

Between 5 and 15, valve 2I I is conditioned to cause clamping of thetubing. Between 11 and 21, valve 2|2 is conditioned to cause the'tubingT to be fed between rolls A and B as indicated in Fig. 1. Between 27 and37 valve 2 is conditioned to cause shafts I3I to be coupled with shaftMI, and shaft I 4| to be unlatched from gear I26. After feeding thetubing and between 56 and 60, valve 2 I3 is conditionedto cause rolls Ato move to A in Fig. 2, to effect the lefthand bendingof tubing T.Between 126 and 136, valve 2 II is conditioned to cause unclamping thetubing which actually takes place before the feeder retracts in responseto conditioning of valve 2I2 between 131 and 141. Between 126 and 136,valve 2 I3 is conditioned to cause roll A to return to normal positionas shown in Fig. 3.

Between 177 and 187, valve 2| I is conditioned to cause clamping of thetubing. Between 183 and 193 valve 2I2 is conditioned to cause the tubingto be fed as indicated in Fig.4, and valve 2H! is conditioned to causeshafts. I3I to be uncoupled from shaft I 4| and shaft I4I to be latchedto gear I 28. After feeding the tubing and between 228 and 238, valve2I5 is conditioned to cause movement of roll B to position B indicatedin Fig. 5 to effect right-hand bending of the tubing. Between 304 and314, valve 2I5 is conditioned to cause return of roll B to normalposition as shown in Fig. 6.

Reversal of shaft couplings is accompanied by reversal of position ofsupports 01' sockets I89 and H8.

Operation of the machine continues until the counter 2' (Fig. 44) timesout, or counts from zero to a number at which the counter is set tocause its switch to open. When this switch opens relay. coil 256 (Fig.43) is open circuited. Relay switch 255 opens, the solenoid 238 isdeenergized and the clutch 228 (Fig. 50). disengages. The solenoid 25!is also deenergized and valve 258 causes vent pipe, 288 to be openedand. valves 2 89 and 28I open by-passes so that the pumps 28! and 282run idle. Thetubing is removed and the tubing guide isloaded. Thecounter is reset to the desired number above zero which operation causescounter controlled switch to close. The relay switch 255 closes andsolenoid 238 is energized to engage clutch 226 and solenoid 251 isenergized to cause valve 258 to close vent 288 and valves 288 and 29!close the pump by-passes.

If the counter is set to count up to an even number, such as 16, thecounter switch will open upon the completion of eight revolutions ofshaft 222 which causes eight complete machine cycles to produce 16 bendsin the tubing. If an odd number of bends, such as 15, is desired, thecounter is set at 15 so that the counter switch opens upon thecompletion of 7 A revolutions of

